My Korean dictionary defines 上達 (상달) as "to report (to a superior)," and defines 下達 (하달) as "to command" or "to order." 達 (달) means "to communicate" or "to convey," so 上達 literally means "to a superior (上) communicate (達)," and 下達 (하달) literally means "to an inferior (下) communicate (達)." When you communicate with a superior, you are either reporting to him or giving him advice or opinion, but in both cases you are being very polite. When you communicate with an inferior, you are usually giving an order, without worrying about being polite. Therefore, trying to be a gentlemen, I would like to suggest the following translation: